{"instruction": "You are an expert in named entity recognition. Please extract entities that match the schema definition from the input. Return an empty list if the entity type does not exist. Please respond in the format of a JSON string.", "schema": ["Chemical"], "input": "The headwater inputs generate chronic base flow concentrations of total mercury of about 1 , 000 ng / L , but most of the annual export of mercury from the system appears to originate farther downstream ."}
{"Chemical": ["mercury"]}